Polymerization of cyclic olefins

ABSTRACT

A catalyst and process for the polymerization of cyclic olefins, such as dicyclopentadiene, are disclosed. The catalyst includes a transition metal compound, a co-catalyst and a boron halide promoter. Polymerization can be carried out in a reaction injection molding process to prepare a thermoset molded article having high Tg and superior flexural strength.

This is a continuation of application Ser. No. 770,749, filed Oct. 3,1991, now abandoned, which is a continuation of Ser. No. 548,445, filedJul. 5, 1990 now abandoned, which was a continuation of Ser. No.278,101, filed Nov. 30, 1988 now abandoned.

BACKGROUND OF THE INVENTION

This invention relates to the polymerization of cyclic olefins. In oneembodiment, the invention relates to a catalyst for the reactioninjection molding of dicyclopentadiene. In another aspect, the inventionrelates to a dicyclopentadiene polymer having superior flexuralstrength.

Cyclic olefins are subject to ring-opening metathesis polymerization toproduce thermoset polymers having physical properties making themsuitable for structural and electronic applications, such as molded carparts and electrical laminates. Such polymerizations are commonlycarried out in reaction injection molding (RIM) processes, in which themetathesis catalyst and the monomer are charged to a heated mold andpolymerization of the monomer and forming of the polymer into thedesired shape are carried out simultaneously in the mold.

In such RIM processes, it is important that the polymerization reactionoccur rapidly and with as complete incorporation of the charged monomersas possible. It has been found in molding polydicyclopentadiene, forexample, that the presence of unreacted monomers results in a moldedpart having a very unpleasant odor and less than optimum physicalproperties, in commercial RIM processes, it is economically desirablethat the process be carried out in as short a cycle time as possible andat starting mold temperatures at or near room temperature. It is alsoadvantageous to be able to use an impure monomer stream and thus avoidextensive purification of the monomer prior to polymerization.

One metathesis catalyst system which has been successfully used in RIMprocesses is the combination of a phenol-treated transition metal salt,such as WOCl₄ or WCl₆, and a co-catalyst such as an aluminum or tincompound. In particular, a phenol-substituted tungsten combined with atin hydride has been found highly efficient for monomer incorporationinto the polymer. This catalyst also is highly active in a relativelyimpure dicyclopentadiene feed stream. It would be desirable to furtherreduce the cycle time and polymerization temperature for RIM processescatalyzed by this and other transition metal catalysts. It would also bedesirable to reduce the amount of the costly tungsten and tin componentsof the catalyst without sacrificing catalyst activity. It would furtherbe desirable to improve the properties, such as flexural strength, of adicyclopentadiene polymer.

It is therefore an object of this invention to provide an improvedcatalyst for the polymerization of cyclic olefins. In one embodiment, itis an object of the invention to provide a reaction injection moldingprocess in which dicyclopentadiene is polymerized rapidly at relativelylow mold temperatures. In a further embodiment, it is an object of theinvention to provide a dicyclopentadiene polymer having superiorflexural strength.

BRIEF DESCRIPTION OF THE INVENTION

According to the invention, a process and catalyst for thepolymerization of cyclic olefins are provided, wherein a cyclic olefinis polymerized in the presence of a catalyst comprising (a) a transitionmetal compound, (b) a co-catalyst, and (c) a boron halide compound. Thepolymerization is preferably carried out in the presence of an organotin hydride or organo aluminum co-catalyst. In a specific embodiment,the invention process involves the use of an aryloxy-substitutedtungsten halide or oxyhalide, a tin hydride co-catalyst and a borontrifluoride promoter for the reaction injection molding ofdicyclopentadiene. The invention catalyst and process enable the rapidpolymerization of dicyclopentadiene at relatively low mold temperaturesor relatively low levels of the catalyst and cc-catalyst, and enable theproduction of dicyclopentadiene polymers having excellent properties.

DETAILED DESCRIPTION OF THE INVENTION The Catalyst

The polymerization catalyst includes a transition metal compound. Thetransition metal is preferably, because of the high activity of theresulting catalyst for dicyclopentadiene polymerization, molybdenum ortungsten. The transition metal compound (or starting material therefor)is generally in the form of a salt, including such salts as halides,including oxyhalides. Suitable halides include chloride, bromide andfluoride. The transition metal halide is preferably one in which thehalide is present in a molar amount of at least three atoms per atom oftransition metal. Examples of such transition metal halides includemolybdenum oxytetrachloride, molybdenum oxytrichloride, molybdenumtrioxyhexachloride, molybdenum trioxypentachloride, molybdenumoxytetrafluoride, tungsten hexachloride, tungsten oxytetrachloride, andtungsten oxytetrabromide. The preferred transition metal compounds,because of their high activity for dicyclopentadiene polymerization, aretungsten hexachloride, tungsten oxytetrachloride, molybdenumoxytrichloride, and mixtures thereof. The transition metal compound willgenerally be present in the polymerization reaction mixture in an amountof from about 0.001 to about 5, preferably from about 0.005 to about 1,most preferably from about 0.01 to about 0.1 mole percent, based onmoles of cyclic olefin monomer present.

The transition metal compound preferably includes the reaction productof the above transition metal salt with an alcohol or phenol forsolubilization and enhanced activity of the transition metal salt. Thesolubilizing compound can be, for example, phenol or an aryl- oralkyl-substituted phenol such as o-, m- and p-cresol; 2-, 3- and4-ethylphenol; 2-, 3- and 4-propylphenol; 2-, 3- and 4-isopropylphenol;2-, 3- and 4-butylphenol; 2-, 3- and 4-tertbutylphenol; 2-, 3- and4-phenylphenol; 2,4- and 2,6-diisopropylphenol; 2,4- and2,6-diisobutylphenol; 2,4- and 2,6-di-tertbutylphenol;2,6-di-tertbutyl-4-methylphenol; 2,4- and 2,6-diphenylphenol. The phenolcan be a halophenol such as, for example, 2-, 3- and 4-fluorophenol;2,3-, 2,4-, 2,5-, 2,6-, 3,4- and 3,5-difluorophenol; 2,3,4-, 2,3,5-,2,3,6-, 3,4,5-, 2,4,5- and 2,4,6-trifluorophenol; 2,3,4,5-, 2,4,5,6- and2,3,5,6-tetrafluorophenol; pentafluorophenol; and the correspondingbromo- and chlorophenols. The phenol can be a haloalkyl-substitutedphenol such as, for example, 3-trifluoromethylphenol,2-trichloromethylphenol, 4-trifluoromethylphenol,2-trifluoromethylphenol, 3-chlorodifluoromethylphenol,3-dichlorofluoromethylphenol and 3-tribromomethylphenol. Suitablealcohols include, for example, ethanol, isopropanol, t-butanol,octadecanol and the like. Mixtures of such alcohols and phenols can alsobe used.

The phenol will generally be present in the catalyst in an amount ofabout 1 to about 3 moles per mole of the transition metal, preferablyfrom about 1.5 to about 2.5 moles. The reaction product, oraryloxy-substituted transition metal compound, can be prepared, forexample, by contacting, under an oxygen-free inert atmosphere, thealcoholic or phenolic compound and the transition metal compound in aninert organic liquid with mild heat and removal of generated hydrogenhalide. Suitable inert organic liquids for the reaction include, forexample, cyclopentane, cyclohexane, benzene, toluene, xylene,chlorobenzene and dichlorobenzene. The inert organic liquid is thenpreferably distilled off under vacuum, and the solid residue isdissolved in dry, degassed cyclic olefin monomer.

The Co-Catalyst

The catalyst component can be used in combination with one or moreco-catalyst compounds. Such co-catalysts can include, for example, anorgano aluminum compound, including trialkyl aluminum, alkylaluminumdihalides, dialkylaluminum halides, or alkyl(alkyloxy) aluminum halides,or an organo tin hydride compound, the latter including compounds whichcan be represented by the formula Sn(R)₃ H, in which each R is selectedindependently from hydrogen, substituted or unsubstituted aryl, or C₁₋₂₀alkyl. Specific examples of such co-catalysts include ethyl aluminumchloride, diethyl aluminum chloride, tributyl tin hydride, tripentyl tinhydride, diphenyl tin dihydride, trioctyl tin hydride,methyldicyciohexyl tin hydride, cyclopentyldimethyl tin hydride,triphenyl tin hydride and phenyldimethyl tin hydride. Substituents onthe R groups in the above formula can include, for example, C₁₋₂₀ alkoxyand halides.

The amount of the co-catalyst present in the catalyst composition willvary depending upon the specific components present and the reactionconditions. In general, a tin-containing co-catalyst will be present ina molar amount of from about 15:1 to about 1:1, preferably from about8:1 to about 2:1, based on moles of transition metal in the catalyst,while an organo aluminum halide will generally be present in a molarratio of about 8:1 to about 1:1.

The catalyst system may include a moderator to delay the initiation ofpolymerization if the selected catalyst and co-catalyst cause instantpolymerization upon contact. Ethers, esters, ketones, nitriles and polarcyclic olefins are among suitable moderators for catalyst systems madeup of tungsten catalysts and alkyl aluminum halide co-catalysts. Ethylbenzoate, butyl ether bis(2-methoxyethyl)ether and polar cyclic olefinsare preferred moderators. Moderators are generally not necessary forcatalyst systems having a tin hydride co-catalyst.

The Boron Promoter

The invention catalyst includes a boron halide promoter, including borontrihalides, boron trihalide complexes and tetrahaloborates. The promotercan be, for example, such boron halides as boron tribromide, borontrifluoride, boron trifluoride diethyl ether complex, boron trifluoridedibutyl ether complex, boron trifluoride ethylamine, tetrafluoroboricacid diethyl ether, methyl boron difluoride, phenyl boron dichloride,triphenylmethyl ammonium fluoroborate, tetrafluoroborate,bis(2-ethyl-1-hexyl)ammonium tetrafluoroborate, boron trichloridedimethylsulfide, boron trifluoride alcohol complexes, and the like. Theboron compound will be present in the polymerization reaction mixture inan amount effective to promote polymerization of the cyclic olefinmonomer, generally from about 0.001 to about 10 moles, preferably fromabout 0.05 to about 2 moles, per mole of transition metal. Thepresently-preferred boron halides, because of their high activity andstability, are boron trifluoride and its ethyl ether and butyl ethercomplexes.

Catalyst Preparation

The preferred catalyst composition of the invention includes anaryloxy-substituted tungsten or molybdenum oxychloride catalyst,optionally combined with an aryloxy-substituted tungsten hexachloride ormolybdenum pentachloride, a tributyl or triphenyl tin hydrideco-catalyst, and a boron trifluoride complex promoter. This catalyst hasbeen found to exhibit high activity in the polymerization ofdicyclopentadiene and high monomer conversion in a reaction injectionmolding process having a short induction time and relatively lowpolymerization temperature.

The above catalyst composition is preferably prepared by reacting abouttwo moles of a substituted phenol with one mole of tungsten hexachlorideor tungsten oxytetrachloride, or mixture thereof, in dry inert solventsuch as toluene at a temperature within the range of about 25° to about95° C. under oxygen-free argon. Hydrogen chloride by-product is sweptout of the reaction and the toluene is distilled off under vacuum. Thereaction product is conveniently dissolved in dry, degasseddicyclopentadiene or other liquid monomer to be polymerized, to make asolution about 2 to 10 weight percent in bisphenoxy tungsten compound,which can be diluted with additional monomer to achieve the desiredconcentration of catalyst. The tin co-catalyst is generally combinedwith the transition metal catalyst in the reaction mixture as a solutionof the monomer to be polymerized. The boron halide promoter is generallycombined with the transition metal and/or tin co-catalyst solution.

Polymerization

The polymerization process of the invention involves contacting one ormore cyclic olefin monomers with the transition metal component in thepresence of the co-catalyst and the boron halide promoter. Suitablecyclic olefin monomers and comonomers include those of the norbornenetype which can be represented by the structural formulas ##STR1## inwhich each R is selected independently from hydrogen, C₁₋₂₀ alkyl, C₁₋₂₀alkenyl, aryl and, with R groups linked together through carbon atoms,saturated and unsaturated cyclic hydrocarbon groups. Included in suchmonomers and comonomers are dicyclopentadiene, norbornene, norbornadieneand 5-(2-propenyl)norbornene. Commercial cyclic olefins are available atvarious levels of purity, ranging from about 92 to about 99.9, the upperpurity ranges being the result of distillation and further treatment forremoval of contaminants and olefins which would be co-polymerized underpolymerization conditions. As a general rule, transition metal catalystsemploying an alkyl aluminum compound as co-catalyst require ahigh-purity monomer for acceptable polymerization activity, while theuse of a tin co-catalyst permits the use of lower purity,technical-grade (83-95%) dicyclopentadiene monomer. An advantage of theinvention catalyst is that it is very active in relatively impure(90-95%) dicyclopentadiene.

The invention polymerization process is preferably carried out byreaction injection molding (RIM), in which a solution of the catalyst,preferably in the monomer liquid to be polymerized, is injected into amold simultaneously with the monomer, in liquid form, to be polymerized.The catalyst is generally employed in a molar ratio of RIM monomer totransition metal (mole:mole) of from about 100:1 to about 12,000:1,preferably about 1000:1 to about 8000:1, most preferably about 2500:1 toabout 7000:1.

In a preferred RIM polymerization technique, a stream of the transitionmetal catalyst component in the monomer to be polymerized and a monomerstream containing the tin co-catalyst are combined in the mixing head ofa RIM machine just prior to injection of the combined stream into amold. The boron compound is injected into the mixing head with thetransition metal stream, with the co-catalyst stream, or in a separatemonomer solution stream.

The initial mold temperature will generally be within the range of about20° to about 130° C., preferably about 35° to about 100° C. The moldpressure is generally within the range of about 10 to about 50 psi.After injection of the catalyst and monomer into the mold, there is aninterval of time, called the "induction time," before onset of a rapidexotherm from the exothermic polymerization reaction. In a commercialRIM process, this induction time should be sufficiently long to permitfilling of the mold, but no longer than about 2 minutes, preferably lessthan thirty seconds. Once the polymerization reaction is initiated,polymerization should occur quite rapidly, usually within about 10seconds to about 1 minute, and is accompanied by a rapid rise intemperature.

Various optional components can be present in the reaction mixtureduring polymerization, including solvents, fillers, anti-oxidants, flameretardants, blowing agents, stabilizers, foaming agents, pigments,plasticizers, reinforcing agents and impact modifiers. Particularlypreferred is the addition of from about 1 to about 10 weight percent,based on the weight of the monomer, of an elastomer for impactmodification of the polymer. These components are most convenientlyadded to the reaction as constituents of one or more of the reactionmixture streams, as liquids or as solutions in the monomer.

After the polymerization reaction is complete, the molded object may besubjected to an optional post-cure treatment at a temperature in therange of about 100° to about 300° C. for about 1 to 24, preferably about1 to 2 hours. Such a post-cure treatment can enhance certain polymerproperties, including glass transition temperature.

The Polymer

The invention process prepares a crosslinked dicyclopentadienehomopolymer or copolymer having excellent physical properties. Thepresently preferred polydicyclopentadiene product is a crosslinkedpolymer containing at least about 90 percent dicyclopentadiene monomerunits and having a flexural strength of at least about 10,500 psi,preferably greater than about 11,500 psi, and a Tg of at least about125° C. (DSC at 20° C./min). Polymer prepared in a reaction injectionmolding process using the invention catalyst has been found to have ahigh crosslink density and to exhibit a percent swell in toluene of lessthan about 200, often less than about 120%. The polymer is useful inapplications such as structural composites, for example, in theautomobile industry, and in electrical applications such as printedcircuit boards.

EXAMPLES

Certain specific embodiments of the invention are described in thefollowing examples, in which dicyclopentadiene was polymerized underlaboratory-scale reaction injection molding conditions using atungsten-based catalyst, a tin co-catalyst and a boron promoter. Thearyloxy-substituted tungsten catalysts used in the examples wereprepared by reacting tungsten hexachloride or tungsten oxytetrachlorideor mixtures thereof with two equivalents or a slight excess of2,6-diisopropylphenol in dry toluene at 25°-90° C. under oxygen-free,dry argon and, after the hydrogen chloride by-product had been sweptfrom the reaction, distilling the toluene under vacuum. The residue wasdissolved in dry, degassed dicyclopentadiene (about 93% puritycontaining up to 7% C₉ and C₁₀ olefins) to make a 5-8 weight percentsolution (referred to as catalyst master solution). Described procedureswere carried out in a nitrogen dry box or under purified argonatmosphere.

Example 1

A 30-mL dried serum bottle with a stir bar was charged with an amount ofaryloxy-substituted tungsten hexachloride catalyst master solution toprovide 0.059 mmol of tungsten catalyst, an amount of boron trifluorideetherate as a 0.5 weight % solution in dicyclopentadiene to provide0.030 mmol of the boron compound, and additional dry, degasseddicyclopentadiene (93%) such that the total amount of dicyclopentadienein the final polymerization mixture was 16 g. To this stirred solutionwas added by syringe a solution of 0.22 mmol tributyltin hydride in DCPDat room temperature. The mixture was stirred for 20-30 seconds at roomtemperature, and then placed in an oil bath at 90° C. The temperaturenear the center of the reaction mixture was monitored by means of athermocouple probe. After about six seconds, at which time thetemperature in the center of the reaction mixture had reached 40° C., avery rapid, exothermic polymerization occurred. After one minute in thebath, the internal temperature of the polymerizing mass had reached amaximum of 189° C. and had begun to decline gradually. Theseobservations are tabulated in Table 1.

Examples 2-10

The polymerizations of Examples 2-10 and comparative Example A wereconducted essentially as described in Example 1. In Example A, the borontrifluoride etherate was omitted, which resulted in a longer inductiontime, a higher induction temperature prior to onset of the exothermicpolymerization, and a longer time to reach the maximum exothermictemperature compared to the polymerizations which employed borontrifluoride complex. Polymerization mixtures and observations aretabulated in Table 1.

                                      TABLE 1                                     __________________________________________________________________________    Polymerization of                                                             Dicyclopentadiene Using Aryloxy-substituted WCl.sub.6 Catalyst                W comp.   BF.sub.3 (Et.sub.2 O)                                                               But.sub.3 SnH                                                                      Induction  Exotherm Maximum                              Example                                                                            (mmol)                                                                             (mmol)                                                                              (mmol                                                                              Time, min.                                                                          T, °C.                                                                      Time, min.                                                                          T, °C.                           __________________________________________________________________________    1    0.059                                                                              0.030 0.22 0.1   40   1.0   189                                     A    0.059                                                                              --    0.22 6.4   68   8.0   198                                     2    0.059                                                                              0.0062                                                                              0.22 3.8   <100 5.2   194                                     3    0.059                                                                              0.0116                                                                              0.22 1.9   40   4.1   189                                     4    0.059                                                                              0.0124                                                                              0.22 1.4   47   2.1   208                                     5    0.059                                                                              0.015 0.22 NR.sup.a                                                 6    0.059                                                                              0.008 0.22 1.4   48   2.0   188                                     7    0.029                                                                              0.008 0.22 1.9   48   3.0   190                                     8    0.029                                                                              0.0124                                                                              0.11 1.4   33   2.8   196                                     9    0.029                                                                              0.015 0.11 NR.sup.a                                                 10   0.0196                                                                             0.015 0.22 3.1   42   4.3   203                                     __________________________________________________________________________     .sup.a Boron trifluoride etherate was combined with the tin hydride in        DCPD and the combined solution was then immediately added to the solution     of tungsten compound in DCPD; the mixture gelled but an exothermic            polymerization did not occur because of incomplete solubility of these        samples of boron trifluoride etherate.                                   

Examples 11-37 and Comparative Examples B-K

The polymerizations shown in Table 2 were conducted essentially as inExample 1, except that the aryloxy-substituted tungsten catalyst wasprepared from tungsten oxytetrachloride.

Comparative Examples C and D were conducted in the absence of tinhydride. Comparative Example H employed a low level of tin hydride,which resulted in polymerization after a relatively long induction time.In the presence of boron trifluoride etherate (Examples 25 and 26), theinduction time was improved substantially for reaction mixturescontaining this low level of tin hydride. Examples 27-29 and ComparativeExample I show that a Sn/W mol ratio of about 1:1 resulted in a verysluggish polymerization and a temperature rise not substantially abovethat of the heating bath, even in the presence of boron trifluoride.Examples 33 and 34 were conducted with dibutyl ether complex of borontrifluoride in place of the diethyl ether complex. Examples 35-37 wereconducted with boron tribromide in place of boron trifluoride etherate.

                                      TABLE 2                                     __________________________________________________________________________    Polymerization of                                                             Dicyclopentadiene Using Aryloxy-substituted WOCl.sub.4 Catalyst               W comp.   BF.sub.3 (Et.sub.2 O)                                                               But.sub.3 SnH                                                                      Induction  Exotherm Maximum                              Example                                                                            (mmol)                                                                             (mmol)                                                                              (mmol)                                                                             Time, min.                                                                          T, °C.                                                                      Time, min.                                                                          T, °C.                           __________________________________________________________________________    B    0.059                                                                              --    0.22 3.6   53   5.1   203                                     11   0.059                                                                              0.0124                                                                              0.22 2.4   39   3.9   200                                     12   0.059                                                                              0.030 0.22 0.2   43   1.3   156                                     13   0.059                                                                              0.059 0.22 0.2   33   0.8   179                                     14   0.059                                                                              0.118 0.22 0.2   33   0.8   172                                     C    0.039                                                                              0.039 --   NR                                                       D    0.039                                                                              0.078 --   NR                                                       E    0.039                                                                              --    0.312                                                                              2.8   62   3.5   196                                     15   0.039                                                                              0.0098                                                                              0.312                                                                              2.5   46   3.2   187                                     16   0.039                                                                              0.0195                                                                              0.312                                                                              0.2   49   0.6   185                                     F    0.039                                                                              --    0.156                                                                              4.4   63   5.8   209                                     17   0.039                                                                              0.019 0.156                                                                              0.6   37   1.6   179                                     18   0.039                                                                              0.039 0.156                                                                              0.1   35   1.0   197                                     G    0.039                                                                              --    0.156                                                                              4.1   54   5.6   198                                     19   0.039                                                                              0.020 0.156                                                                              0.2   35   1.1   193                                     20   0.039                                                                              0.020 0.156                                                                              0.8   37   1.5   201                                     21   0.039                                                                              0.039 0.098                                                                              0.9   37   1.5   183                                     22   0.039                                                                              0.0098                                                                              0.233                                                                              2.3   38   3.4   198                                     23   0.039                                                                              0.0195                                                                              0.233                                                                              1.4   35   2.7   189                                     24   0.039                                                                              0.039 0.233                                                                              0.5   35   1.4   183                                     H    0.039                                                                              --    0.079                                                                              11.8  96   12.9  191                                     25   0.039                                                                              0.020 0.079                                                                              1.6   44   2.7   183                                     26   0.039                                                                              0.039 0.079                                                                              1.4   33   2.7   201                                     I    0.039                                                                              --    0.039                                                                              NE                                                       27   0.039                                                                              0.039 0.039                                                                              NE                                                       28   0.039                                                                              0.039 0.039                                                                              NE                                                       29   0.039                                                                              0.078 0.039                                                                              NE                                                       30   0.020                                                                              0.020 0.080                                                                              3.0   41   4.4   177                                     31   0.020                                                                              0.040 0.080                                                                              1.9   40   2.9   187                                     J    0.017                                                                              --    0.039                                                                              NE                                                       32   0.017                                                                              0.020 0.039                                                                              2.4   53   10.6  122                                     with BF.sub.3 (But).sub.2 O                                                   33   0.059                                                                              0.029 0.22 <0.1  25   0.3   202                                     34   0.039                                                                              0.020 0.156                                                                              0.7   33   1.5   194                                     with BBr.sub.3                                                                K    0.059                                                                              --    0.22 2.4   50   3.5   206                                     35   0.059                                                                              0.059 0.22 2.2   58   2.9   188                                     36   0.059                                                                              0.029 0.22 2.0   64   3.2   196                                     37   0.059                                                                              0.015 0.22 2.3   71   3.1   220                                     __________________________________________________________________________     NE = no exothermic polymerization; gel formation.                             NR = little or no polymerization apparent.                               

Examples 38-41 and Comparative Examples L-P

The polymerizations of these examples were carried out essentially as inExample 1, except that the aryloxy-substituted tungsten catalyst wasprepared from a mixture of tungsten hexachloride and tungstenoxychloride in a mole ratio of 90/10. Example 38 was carried out with anethylamine complex of boron trifluoride in place of the diethyl ethercomplex. Examples 39 and M were carried out with triphenyltin hydride inplace of tributyltin hydride. Examples 40 and N were carried out withetetrabutyltin in place of tributyltin hydride. Examples 41 and P werecarried out with bis(tributyltin) [hexabutylditin] in place oftributyltin hydride.

                                      TABLE 3                                     __________________________________________________________________________    Polymerization of Dicyclopentadiene                                           Using Aryloxy-substituted WCl.sub.6 /WOCl.sub.4 Catalyst                                                            Exotherm                                W comp.   BF.sub.3 (Et.sub.2 O)                                                                 But.sub.3 SnH                                                                           Induction Maximum                                 Example                                                                            (mmol)                                                                             (mmol)  (mmol)    Time, min.                                                                          T, °C.                                                                     Time, min.                                                                          T, °C.                     __________________________________________________________________________    L    0.059                                                                              --      0.22      3.0   97  3.8   202                                         with BF.sub.3 EtNH.sub.2                                            38   0.059                                                                              0.063   0.22      1.9   57  2.5   208                                                 with (Ph).sub.3 SnH                                         M    0.059                                                                              --      0.353     3.4   53  4.2   227                               39   0.059                                                                              0.059   0.353     0.2   26  0.9   185                                                 with (C.sub.4 H.sub.9).sub.4 Sn                             N    0.059                                                                              --      0.353     NR                                                40   0.059                                                                              0.059   0.353     NR                                                                  with [(C.sub.4 H.sub.9).sub.3 Sn--].sub.2                   P    0.059                                                                              --      0.353     NR                                                41   0.059                                                                              0.059   0.353     NR                                                __________________________________________________________________________     NE = no exothermic polymerization; gel formation.                             NR = little or no polymerization apparent.                               

Example 42

A polymerization was conducted essentially as described in Example 1with tungsten hexachloride (0.059 mmol) in place of thearyloxy-substituted tungsten compound, boron trifluoride etherate (0.059mmol), and tributyltin hydride (0.354 mmol) in a total of 16 gdicyclopentadiene. After 5.9 minutes in the 90° C. bath, at which timethe internal temperature of the polymerization mixture was 89°, anexothermic polymerization occurred which reached a maximum temperatureof 134° C. after an additional 3.7 minutes. By comparison, when theboron trifluoride etherate was omitted, the polymerization conductedwith tungsten hexachloride and tributyltin hydride gelled but did notcause a temperature rise substantially above the temperature of theheating bath.

Examples 43-45

The polymerization was conducted similarly to that of Examples 11-32,except that, instead of combining the boron trifluoride etherate withthe tungsten solution, the boron trifluoride was combined with thetributyltin hydride in dicyclopentadiene before addition to the tungstencompound. In Example 43, the solution containing boron trifluorideetherate and tributyltin hydride was prepared and used after one day. InExamples 44 and 45, the solution was used in the polymerization afterstanding at room temperature for two weeks and six weeks, respectively.

                                      TABLE 4                                     __________________________________________________________________________    Polymerization of Dicyclopentadiene                                           Using Aryloxy-substituted WOCl.sub.4 Catalyst                                                                       Exotherm                                W comp.   BF.sub.3 (Et.sub.2 O)                                                                 But.sub.3 SnH                                                                           Induction Maximum                                 Example                                                                            (mmol)                                                                             (mmol)  (mmol)    Time, min.                                                                          T, °C.                                                                     Time, min.                                                                          T, °C.                     __________________________________________________________________________    43   0.059                                                                              0.027   0.219     <0.1  25  0.4   190                               44   0.059                                                                              0.027   0.219     <0.1  27  0.9   195                               45   0.059                                                                              0.027   0.219     <0.1  32  1.6   208                               __________________________________________________________________________

Example 46

Using a laboratory-scale RIM molding apparatus, apoly(dicyclopentadiene) plaque was made by feeding equal volumes of twostreams of DCPD monomer (93% purity), one stream containingbis(2,6-diisopropylphenoxy)tungsten oxydichloride catalyst and borontrifluoride butyl ether complex and the second stream containingtributyltin hydride such that the final molded part contained 4000:1DCPD:tungsten catalyst, 4:1 tin hydride: tungsten catalyst, and 1:1boron trifluoride: tungsten catalyst (mole/mole), to a static mixer andthe combined streams immediately injected into a heated (100° C.)aluminum mold with an internal volume of about 7×10×1/2 inches. Themixing time and mold filling was accomplished within about 30 seconds,after which time an exotherm occurred within about another 30 seconds.After about 5 minutes, the polymer was removed from the mold. Physicaltests showed the molded part to have a flexural modulus of 325,000 psi,a flexural strength of 12,200 psi (ASTM D790 at room temperature), anIzod impact of 1.36 ft-lb/in (ASTM D256), an elongation of >5%, and aglass transition temperature (tan δ) of approximately 128° C. Thepolymer showed a swelling in toluene of 91% (immersion for 24 hours atroom temperature).

Example 47

Example 47 was conducted essentially as described above in Example 46,except that 5% elastomer (Kraton™ 1102) was included in the monomerstreams and the boron trifluoride:tungsten catalyst ratio was 0.75.Physical tests on this elastomer-modified polymer gave a flexuralmodulus of 291,000 psi, a flexural strength of 10,270 psi,elongation >5%, Izod impact of 12 ft-lb/in, and a swelling in toluene of109%.

Example 48

The RIM polymerization of Example 46 was repeated except omitting theboron trifluoride promoter and using the higher catalyst levelsnecessary to achieve a similar rate of polymerization in the mold(1300:1DCPD: tungsten catalyst and 6:1 tin hydride: tungsten catalyst(mole/mole)). The molded polymer showed a flexural modulus of 318,000psi, a flexural strength of 8,900 psi, an elongation of 3.1%, and aswelling in toluene of 292%. Another plaque molded under theseconditions showed a flexural modulus of 307,000 psi, a flexural strengthof 8,500 psi, an elongation of 3.0% and an Izod impact of 0.70 ft-lb/in.A molded plaque incorporating 5% Kraton™ 1102 elastomer exhibited anIzod impact strength of 7.70 ft-lb/in, a flexural modulus of 270,000 psiand a flexural strength of 8,700 psi.

I claim:
 1. A metathesis-polymerizable composition comprising(a) atungsten compound which is the reaction product of a tungsten salt and aphenol; (b) from about 1 to about 15 moles, per mole of the tungstencompound, of an organo tin hydride which can be represented by theformula Sn(R)₃ H, in which each R is selected independently fromsubstituted or unsubstituted aryl and C₁₋₂₀ alkyl; (c) a boron halidepresent in an amount of from about 0.001 to about 10 moles per mole ofthe tungsten compound; and (d) a cyclic olefin having a norbornenemoiety present in the composition in an amount within the range of 1000to about 8000 moles per mole of the transition metal.
 2. The compositionof claim 1 in which component (a) is a reaction product of a tungstensalt and an alkyl-substituted phenol.
 3. The composition of claim 2 inwhich the boron halide is present in the composition in an amount withinthe range of about 0.05 to about 2 moles per mole of the tungsten metalcompound.
 4. The composition of claim 1 in which the boron halide isselected from the group consisting of boron trihalides, boron trihalidecomplexes and tetrahaloborates.
 5. The composition of claim 4 in whichthe tungsten salt comprises a compound selected from the groupconsisting of tungsten hexachloride and tungsten oxytetrachloride. 6.The composition of claim 5 in which the phenol is selected from thegroup consisting of t-butyl phenol, t-octyl phenol, nonyl phenol,2,6-diisopropyl phenol and 2,6-di-tert-butyl-4-methylphenol.
 7. Thecomposition of claim 1 in which component (b) is a trialkyl tin hydride.8. The composition of claim 7 in which component (a) is a reactionproduct of a tungsten salt and a phenol selected from the groupconsisting of 2,6-diisopropyl phenol and2,6-di-tertbutyl-4-methylphenol.
 9. The composition of claim 8 in whichthe boron halide is selected from the group consisting of borontribromide, boron trifluoride etherate, boron trifluoride ethylamine andboron trifluoride butyrate.
 10. The composition of claim 7 in which thetrialkyl tin hydride is tributyltin hydride.
 11. The composition ofclaim 1 in which the tungsten salt is a mixture of tungsten hexachlorideand tungsten oxytetrachloride.
 12. The composition of claim 11 in whichthe phenol is selected from halophenols and haloalkyl-substitutedphenols.
 13. The composition of claim 11 in which the boron halide ispresent in the composition in an amount within the range of about 0.05to about 2 moles per mole of the tungsten compound.
 14. The compositionof claim 11 in which component (b) is an alkyl tin compound selectedfrom the group consisting of tributyltin hydride, triphenyltin hydrideand trioctyltin hydride.
 15. A process comprising contacting, underreaction injection molding polymerization conditions, a cyclic olefinmonomer having a norbornene moiety with a composition comprising (a) atungsten compound which is the reaction product of a tungsten salt and aphenol; (b) from about 1 to about 15 moles, per mole of the tungstencompound, of an organo tin hydride which can be represented by theformula Sn(R)₃ H, in which each R is selected independently fromsubstituted or unsubstituted aryl and C₁₋₂₀ alkyl; and (c) a boronhalide present in an amount within the range of about 0.01 to about 10moles per mole of the tungsten compound, for a time sufficient toproduce a solid polymeric molded article.
 16. The process of claim 15 inwhich the cyclic olefin comprises dicyclopentadiene.
 17. The process ofclaim 16 in which the boron halide is selected from the group consistingof boron trihalides, boron trihalide complexes and tetrahaloborates. 18.The process of claim 16 in which the organo tin hydride is selected fromthe group consisting of tributyltin hydride, triphenyltin hydride andtrioctyltin hydride.
 19. The process of claim 16 in which component (a)is a reaction product of at least one of tungsten hexachloride andtungsten oxytetrachloride and a compound selected from the groupconsisting of halophenols, alkyl-substituted phenols andhaloalkyl-substituted phenols.
 20. A process for in-mold polymerizationof a cyclic olefin having a norbornene moiety which comprises(a)introducing into a mold a reaction mixture comprising the cyclic olefin,a catalyst comprising an aryloxy-substituted tungsten compound, fromabout 1 to about 15 moles per mole of the tungsten compound of aco-catalyst selected from organo tin hydride and organo aluminumhalides, and from about 0.001 to about 10 moles of a boron halide, and(b) maintaining the reaction mixture under polymerization conditions fora time sufficient for polymerization of the cyclic olefin and formationof a molded article.
 21. The process of claim 20 in which the boronhalide is selected from the group consisting of boron trihalides, borontrihalide complexes, and boron tetrahaloborates.
 22. The process ofclaim 20 in which the aryloxy-substituted tungsten compound is thereaction product of a tungsten salt and an alkyl-substituted phenol andthe organo tin hydride is selected from the group consisting oftributyltin hydride, triphenyltin hydride and trioctyltin hydride. 23.The process of claim 20 in which the reaction mixture is introduced intoa mold at an initial mold temperature within the range of about 20° toabout 130° C.
 24. The process of claim 20 in which the reaction mixtureis the product of mixing a first stream comprising thearyloxy-substituted tungsten compound and a second stream comprising theorgano tin hydride, wherein at least one of said first and secondstreams further comprises the cyclic olefin monomer and at least one ofsaid first and second streams further comprises the boron halide. 25.The process of claim 24 in which the boron halide is present in thereaction mixture in an amount within the range of about 0.05 to about 2moles per mole of the aryloxy-substituted tungsten compound.
 26. Theprocess of claim 24 in which the boron halide is selected from the groupconsisting of boron trifluoride, boron trifluoride etherate and borontrifluoride butyrate.
 27. The process of claim 22 in which thetransition metal salt is selected from the group consisting of tungstenhexachloride, tungsten oxytetrachloride and molybdenum oxytrichloride.28. The process of claim 27 in which the alkyl-substituted phenol isselected from the group consisting of 2,6-diisopropyl phenol and2,6-di-tert-butyl-4-methylphenol.
 29. The process of claim 20 in whichthe cyclic olefin is selected from the group consisting ofdicyclopentadiene, norbornene, norbornadiene and5-(2-propenyl)norbornene.